I guess it doesn’t make any difference now. I reassembled the computer and now I get a message 28 “RX50 Controller Board" failure during POST. I’ve taken it apart and put it back together several times, but I cannot clear the failure. This really has been a bad day!
smp -- Stephen M. Pereira Bedford, NH 03110 KB1SXE > On Apr 12, 2017, at 3:07 PM, Warner Losh <i...@bsdimp.com> wrote: > > On Wed, Apr 12, 2017 at 1:00 PM, Stephen Pereira > <spereira1...@comcast.net> wrote: >> Thanks for your response. >> >> Just to be certain, I just tore it all down and reconfirmed, in case my >> memory was playing any tricks. >> >> I have a PC-100B with no expansion card. >> >> Thanks again for the advice. > > Bummer. The cards come up from time to time in different places, but > there's none on ebay right now. Last summer there were like 5, > including one that had an 8087 coprocessor option... > >> smp >> -- >> Stephen M. Pereira >> Bedford, NH 03110 >> KB1SXE >> >> On Apr 12, 2017, at 2:20 PM, Warner Losh <i...@bsdimp.com> wrote: >> >> On Wed, Apr 12, 2017 at 11:06 AM, Stephen Pereira via cctech >> <cct...@classiccmp.org> wrote: >> >> I’m looking for expansion memory for my DEC Rainbow. >> >> I currently have 128K RAM, and I’d like to have 256K RAM, so I can actually >> use the Lotus 1-2-3 that I recently purchased (without thinking). >> >> Any suggestions? >> >> >> So is this a 100A with a 64k expansion card? Or is it the 100B with no card? >> >> If you have the 100A and a 3-bank expansion card, you should be able >> to remove the 64k chips that are on there and replace them with 256k >> chips. You should be able to take it to 832k with 27 256kbit DRAM >> chips. 41256-120's in DIP 16 if I recall correctly. Need to set the >> DIP switches correctly. This is the easiest path forward, if you are >> lucky enough to have this configuration, since chips are easy to get, >> relatively speaking, and last time I priced them, they were ~0.70 each >> so this will set you back ~$20 from JAMECO. You'll want an anti-static >> setup to do this, since the BBSs were full of people that had done >> this w/o adequate setup blowing up their card / chips. IMHO, if you >> are going this route, it's not worth messing with 64k chips since the >> price difference is tiny and the win for 3 banks of 256k on the >> Rainbow is big. >> >> If you have a 100B with no expansion card, I can't help... The >> expansion card is the hard bit these days... >> >> Warner >> >>